1. Field of the Invention
The present invention relates generally to test equipment, and more particularly to a system and method for verifying central office (CO) wiring associated with line sharing.
2. Background of the Invention
The Federal Communications Commission (FCC) has promulgated rules that require Incumbent Local Exchange Carriers. (ILEC) to share certain telecommunications resources with Competitive Local Exchange Carriers (CLEC). One of these rules enables a CLEC to use telephone lines of an ILEC, in competition with the ILEC, to offer telecommunications services to customers of the ILEC. Such line sharing arrangement allows the CLEC to provide, for example, digital subscriber line (DSL) services over the same loop that is used by the ILEC for voice communications.
Without the line sharing arrangement, DSL services can be provided by the ILEC using a combined splitter and DSL modem (also known as a digital subscriber line access multiplexer or DSLAM) that are placed at a common location within a CO. Testing or verification of the wiring would not be a difficult task because both voice and data are provided by the ILEC. Under a line sharing arrangement, however, the CLEC's DSLAM is a different unit that is physically separated from the ILEC's splitter. Due to the competitive nature between the ILEC and the CLEC, the ILEC's splitter and the CLEC's DSLAM are physically located in different parts of a CO, even though each of the splitter and the DSLAM is ultimately connected to a common telephone line that serves the same customer. More often than not, the ILEC's splitter and the CLEC's DSLAM are located on separate floors in a building that houses the CO. Such physical separation of the splitter and the DSLAM creates unprecedented complexity associated with testing CO wiring. In some cases, for instance, five two-wire connections between wire terminals are required. This complexity, of course, increases the potential for wiring errors.
Portable telephone test sets are used extensively in the telecommunications industry to establish temporary communications or test lines for proper operation. These test sets are widely referred to as “butt sets.” The term butt sets is used herein to refer to the portable telephone test sets. As known in the art, voice circuits can be “verified” or tested using the CO's embedded Automatic Number Announcement Circuit (ANAC). The verification process typically involves the following steps. First, a technician bridges across the circuit with a conventional butt set. Second, the technician causes the butt set to go off-hook to draw a dial tone. Third, the technician dials the ANAC number. Fourth, the ANAC responds with the telephone number of the telephone line being tested. Fifth, the telephone number provided by the ANAC is used by the technician to verify the line. Unfortunately, this method of verification cannot be used to verify the DSL circuit in a line sharing arrangement in which the splitter and the. DSLAM are physically separated.
To minimize the possibility of faults on the DSL circuit affecting the voice circuit, the industry standard for line sharing requires a blocking capacitor in the splitter. As known in the art, the blocking capacitor prevents the flow of direct current, which signals the switch to provide dial tone. For this reason, the ANAC process described above cannot be used.
There are currently no known products on the market that are specifically designed to verify the DSL circuit under the line sharing arrangement. As a result, technicians of local exchange carriers must improvise a method to verify CO wiring associated with line sharing.
Technicians have attempted to verify the DSL circuit using frequencies higher than those in the voice band to overcome the blocking capacitor. This method is undesirable because it requires a transmitter and a specially made receiver that is adapted to detect high frequencies. A conventional butt set cannot be used as the receiver in this method. The use of the transmitter and the special receiver to verify CO wiring is not considered to be cost-effective. In some situations, several special receivers per CO may be necessary, making this solution more expensive and even less desirable.
Accordingly, there is a need for a system and method that can verify the DSL circuit in a line sharing arrangement in a cost effective manner. Specifically, there is a need for a system and method that can utilize existing conventional butt sets to verify the DSL circuit in a line sharing arrangement.